Method and system for determining the roundness of a golf ball

ABSTRACT

A golf ball is illuminated with diffused back lighting. CCD images of the golf ball are taken while the golf ball is being illuminated with the diffused back lighting. The edge or circumference of the golf ball is captured and sharply defined in the CCD images. The uniformity of the circumference may be determined by evaluating the radius of the object&#39;s circumference in an image, where an image is generated for n points around the circumference of the object, such as every 20° or 30°. By rotating the game ball, preferable with a battery operated stepper motor, the surface of the golf ball can be mapped.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention claims priority to provisional Patent ApplicationNo. 60/654,000 filed Feb. 18, 2005, the entirety of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method, a system and a computerprogram product for determining properties of a golf ball. Moreparticularly, the present invention relates to a method, a device and acomputer program product for determining properties of a golf ball as afunction of orientation using a hand-held portable device.

2. Description of the Prior Art

Golf balls used by ordinary golfers vary in perfection. Imperfectionsmay occur in golf ball manufacture that are not detected. More often,imperfections are introduced to a golf ball during usage of a golf ball.The imperfections that a golf ball is manufactured with and theimperfections introduced during usage of a golf ball affect the golfball's flight on long drives or the golf ball's roll or direction whenputted on a green. As a consequence of golf ball imperfections, thequality of a golfer's game may be reduced by factors not within his orher control. The enjoyment of the game as a challenge of skill is thusadversely affected.

Techniques have been developed to monitor golf ball quality in order toidentify imperfections so that they do not have an impact on a game ofgolf. Techniques developed to determine the spherical shape of a golfball implement gauges, various types of rings, and tubes which may beused. More recently, machine vision techniques have been described fordetermining the orientation of golf balls. These techniques print logoswith respect to golf ball orientation and automation of this printinggreatly improves golf ball manufacturing. This is important as golfersrely on the consistent placement of the logo to orient a ball for play.Other techniques inspect the repeated patterns, such as dimples, foundon golf balls or the game ball to locate the position for printing alogo. The use of special lighting for obtaining CCD images of sphericalobjects, such as golf balls, has been implemented for visual or cameraassisted evaluation of the golf ball patterns. However, the technologiescurrently available rely on visual interpretation of differences betweena reference and the game ball. In addition, the technologies currentlyavailable focus on one kind of potential defect.

Accordingly, there is a need for a device to monitor the differences inproperties between golf balls. There is a need for the device to belightweight, and hand-held. There is a further need for the device toemploy CCD images to assist a golfer in determining the properties of agolf ball. There is a further need for the device to determine a varietyof properties of a golf ball. There is a further need for the device todetermine the properties of a golf ball that directly affect putting.There is a further need for the device to determine a golf ball'sout-of-roundness, size variations (oversized or undersized), balance,and blemishes on the golf ball surface. Also important is the golfball's elastic properties that influence the length of drives.

SUMMARY OF THE INVENTION

According to embodiments of the present invention, a method, a deviceand a computer program product for determining properties of a golf ballas a function of orientation using a hand-held portable device areprovided. The method illuminates a golf ball with diffused backlighting. CCD images of the golf ball are taken while the golf ball isbeing illuminated with the diffused back lighting. The edge orcircumference of the golf ball is captured and sharply defined in theCCD images. The uniformity of the circumference may be determined byevaluating the radius of the circumference at n points around thecircumference, such as every 20° or 30°. The evaluation of the radius iswell known, for example as described in the publication Machine Vision,by E. R. Davies, which is hereby incorporated by reference in itsentirety. By rotating the game ball, preferable with a battery operatedstepper motor, the surface of the golf ball can be mapped. Thegeneration of the CCD images, from an imaging system, such as theScout™, may be triggered by the position of the stepper motor so as tohave a correlation between image and ball position. The use of the logoas a reference point is of value in this regard.

In an embodiment of the invention, the uniformity of the circumferencemay be determined by the imaging system.

In an embodiment of the present invention, the uniformity of thecircumference may be determined by a system separate from the imagingdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

The above described features and advantages of the present inventionwill be more fully appreciated with reference to the detaileddescription and appended figures in which:

FIG. 1 depicts an exemplary functional block diagram of a device inwhich the present invention can find application;

FIG. 2 depicts an exemplary image of a golf ball with diffusive backlighting; and

FIG. 3 depicts an exemplary schematic of the monitoring system 104 shownin FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is now described more fully hereinafter withreference to the accompanying drawings that show embodiments of thepresent invention. The present invention, however, may be embodied inmany different forms and should not be construed as limited toembodiments set forth herein. Appropriately, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the present invention.

According to embodiments of the present invention, a method, a deviceand a computer program product for determining properties of a golf ballas a function of orientation using a hand-held portable device areprovided. The method illuminates a golf ball with diffused backlighting. CCD images of the golf ball are taken while the golf ball isbeing illuminated with the diffused back lighting. The edge orcircumference of the golf ball is captured and sharply defined in theCCD images. The uniformity of the circumference may be determined byevaluating the radius of the object's circumference in an image, wherean image is generated for n points around the circumference of theobject, such as every 20° or 30°. The evaluation of the radius is wellknown, for example as described in the publication Machine Vision, by E.R. Davies, which is hereby incorporated by reference in its entirety. Byrotating the game ball, preferable with a battery operated steppermotor, the surface of the golf ball can be mapped. The generation of theCCD images, from a imaging system, such as the Scout™, may be triggeredby the position of the stepper motor so as to have a correlation betweenimage and ball position. The use of the logo as a reference point is ofvalue in this regard.

FIG. 1 depicts a functional block diagram of a system 100 in which thepresent invention can find application. In the embodiment of FIG. 1, thesystem 100 is a handheld device operable to determine the properties ofa golf ball as a function of the golf ball's orientation using CCDimages of the golf ball at different orientations with diffused backlighting. In the FIG. 1 embodiment of the present invention, the system100 includes a processor (CPU) 102, imaging circuitry 106, memory 110,data 112, display 108, and program 114. In the FIG. 1 embodiment,imaging circuitry 106 is a CCD camera that captures diffused backlighting and generates at least one image of an object, such as a golfball, with diffused back light for determining the uniformity of thecircumference of the object by evaluating the radius of the object'scircumference in the at least one image. In an embodiment of the presentinvention, an image of the object is generated at n points around theobject's circumference. In an embodiment of the present invention, theradius is evaluated at orientations between 20 degrees and 30 degreesaround the circumference and an image is taken at each orientation.

In the FIG. 1 embodiment of the present invention, images of the objectcan be generated in response to the orientation the object as directedby a stepper motor in monitoring system 104 and provided to memory 110.For example, a stepper motor can change the orientation of a golf ballto a new orientation that is 20 degrees from a previous orientation andtake an image of the golf ball at the new orientation. This process canbe repeated until sufficient images of the golf ball are generated atthe different orientations. The images are provided in a code suitablefor further digital signal processing by CPU 102. The CPU 102 is amicroprocessor, such as an INTEL PENTIUM® or AMD® processor, but can beany processor that executes program instructions in order to carry outthe functions of the present invention. In an embodiment of the presentinvention, the images generated by image circuitry 106 are provided to amemory remotely located from system 102 by wirelessly transmission usingnetwork interface 106. In the FIG. 1 embodiment of the presentinvention, memory 110, monitoring system 104, imaging circuit 106, CPU102, display 108 and network interface 116 communicate using bus 1 18

In the FIG. 1 embodiment of the present invention, the memory 110 iscoupled to CPU 102 and stores program 114 and data 112. The data 112includes, but is not limited to, images depicting the object withdiffuse back lighting in different orientations and edge property datarelated to the evaluation of the radius of the object in each image inorder to determine the uniformity of the object. In an embodiment of thepresent invention, the object is a golf ball. In the FIG. 1 embodimentof the present invention, the program 114 provides the functionalityassociated with determining the properties of a golf ball including, butnot limited to, the uniformity of the golf ball's circumference and theelasticity of the golf ball, as executed by the CPU 102. In anembodiment of the present invention, the program 114 is designed todetermine the uniformity of the golf ball's circumference by evaluatingthe edge properties of the golf ball using images of the golf ball takenin different orientation with back lighting at each orientation andpresenting the results of the evaluation on display 108. In anembodiment of the present invention, the program 114 is designed todetermine the elasticity of the golf ball by applying forces to theobject, such as a golf ball, and measuring the return force anddisplaying the magnitude of the return force on the display 108. In anembodiment of the present invention, the program 114 is designed todetermine the balance of the golf ball by rotating the object, such as agolf ball, and measuring the center of gravity and displaying themagnitude of the center of gravity on the display 108.

FIG. 2 depicts an exemplary image of a golf ball with diffused backlighting. In FIG. 2 embodiment of the present invention, theillumination of the golf ball with diffused back lighting provides thecircumference of the golf ball in a sharply defined manner. A pluralityof images like the image of FIG. 2, where the each image is an image ofthe golf ball at a different orientation, can be used to determine theuniformity of the circumference of the golf ball.

FIG. 3 depicts an exemplary schematic of a monitoring system 104 shownin FIG. 1. In an embodiment of the present invention, the monitoringsystem 104 includes a light source 302, a diffuser screen 304, golf ball306, stage and stepper motor assembly 308, battery casing 310,monitoring system housing 312, door 314 and shaft assembly 316. Thelight source 302 illuminates an object for which the uniformity of itscircumference is to be measured with a back light. In an embodiment ofthe present invention, the light source includes, but is not limited to,a filament bulb, a fluorescent bulb, and a solid state light emittingdiode. The light is transmitted through diffuser screen 304. In anembodiment of the present invention, the diffuser screen 304 can be auniformly textured paper, plastic and glass sufficiently opaque suchthat the edges are highlighted but the surface of the golf ball is not.

In the FIG. 3 embodiment of the present invention, the motor assembly308 receives an object, such as a golf ball, to determine the uniformityof the object's circumference and the object's elasticity. In anembodiment of the present invention, the motor assembly 308 includes asstage and a stepper motor. The stage of motor assembly 308 receives anobject, such as a golf ball, for inspection in accordance with thepresent invention. In an embodiment of the present invention, the stagecan have a concave configuration to increase the stability of the objecton the stage. The stepper motor can rotate the object. In an embodimentof the present invention, the stepper motor rotates a golf ball between20 degrees and 30 degrees and triggers a camera to generate an image ofthe golf ball with back light after each rotation so as to map thecircumference of the golf ball using a plurality of images of the golfball. In an embodiment of the present invention, the logo on the golfball can be used a reference point for rotating the golf ball. Batteriesin case 310 powers the stepper motor and light source 302.

The Door E (314) allows for the object to be inserted into monitoringsystem 104 and includes a shaft 316 that centers the golf ball into theconcave surface of the stage to allow for wobble-free rotation of thegolf ball. In an embodiment of the present invention, the shaft 316 ismade from an appropriate plastic, such as nylon, so that the golf ballis supported, but not damaged during inspection. In an embodiment of thepresent invention, the end of this shaft 316 is concave to bettersupport the golf ball. The monitoring system housing houses thecomponents of monitoring system 104 and couples to a camera, such asimaging circuitry 106 having a lens with a short focal lengthappropriate for imaging the golf ball. The shaft 316 may also beelongated and flexible such that on fast rotation by the stepper motor,the balance of the golf ball may be determined. If the center of gravityis the center of the sphere for the golf ball, the ball will rotatewithout wobble. If the center of gravity is not at the center of thegolf ball, the ball will rotate with a wobble, where the maximumexcursion of the wobble is the direction of the center of gravity, thebalance point. Several approaches may be used to determine the balancepoint, e.g., by use of the Scout™ imaging system whose image willidentify wobble and by use of a marking system (not shown) where a inkmark is placed on the ball during rotation at the maximum of the wobble.The ink mark identifies the direction of the balance point such that agolfer can properly place the ball for putting.

The camera records the image of the golf ball and provides this data forevaluation of the edge properties. The camera also contains theelectronics to select the number of images for evaluating the golf ball.Each image requires the stepper motor to change the orientation of thegolf ball. The camera provides a range of options in selecting thenumber of images and therefore orientations for evaluation of the golfball. In an embodiment of the present invention, 6 through 12 images maybe used corresponding to 60° or 30° inspection angles. In an embodimentof the present invention, the data are evaluated by the processor ofsystem 100. In embodiment of the present invention, the data istransferred to a processor and software operable to perform theevaluations of the present invention.

FIG. 4 is an exemplary flow chart for a method of determining theuniformity of the circumference of the object by evaluating the radiusat n points around the object's circumference. The method begins in step402. In step 402, an object, such as a golf ball is positioned on astage of stepper motor. In step 404, the object is illuminated withdiffused back lighting. By illumination with diffuse back lighting, thecircumference of a golf ball is sharply defined. In step 406, a digitalimage of the object with the diffused back lighting is obtained andstored. In step 408, the radius of the object is evaluated at n pointsaround its radius. In step 410, it is determined whether to rotate theobject at a particular angle. If so, the object is rotated and steps 404through 408 are repeated. Otherwise, the uniformity of the object isprovided at step 412.

While specific embodiments of the present invention have beenillustrated and described, it will be understood by those havingordinary skill in the art that changes can be made to those embodimentswithout departing from the spirit and scope of the invention. Forexample, while the present invention concentrates on a single colordigital image and stationary lost object analysis, it is understood thatinformation from a series of images, a moving object or a specificobject might advantageously be used as well. Also, while our applicationto golf balls has options for using UV and visible light, the method isnot dependent on this choice.

1. A method of determining the properties of an object as a function ofthe object's orientation, the method comprising: providing the object tobe evaluated; generating a digital image of the object with diffusedback lighting at a plurality of different orientations; evaluating theradius of the object in each of the digital images of the object withdiffused back lighting; determining a first property of the object,wherein the first property of the object is the uniformity of theobject's circumference based on the evaluation of the radius of theobject in each of the digital images.
 2. The method according to claim1, further comprising illuminating a light source prior to generatingeach digital image.
 3. The method according to claim 2, furthercomprising transmitting light from the light source through a diffusedscreen.
 4. The method according to claim 1, further comprising rotatinga stepper motor prior to generating each digital image.
 5. The methodaccording to claim 1, further comprising storing data pertaining to theradius of the object in each digital image.
 6. The method according toclaim 1, further comprising reporting the object's first property. 7.The method according to claim 1, further comprising applying force tothe object and measuring the return force of the object to determine asecond property of the object, wherein the second property is theelasticity of the object.
 8. An apparatus for determining the propertiesof an object as a function of the object's orientation comprising: aprocessor operable to execute computer program instructions; and amemory operable to store computer program instructions executable by theprocessor, for performing the steps of: generating a digital image ofthe object with diffused back lighting at a plurality of differentorientations; evaluating the radius of the object in each of the digitalimages of the object with diffused back lighting; determining a firstproperty of the object, wherein the first property of the object is theuniformity of the object's circumference based on the evaluation of theradius of the object in each of the digital images.
 9. The apparatusaccording to claim 8, further comprising computer program instructionsexecutable by the processor, for performing the step of illuminating alight source prior to generating each digital image.
 10. The apparatusaccording to claim 9, further comprising computer program instructionsexecutable by the processor, for performing the step of transmittinglight from the light source through a diffused screen.
 11. The apparatusaccording to claim 8, further comprising computer program instructionsexecutable by the processor, for performing the step of rotating astepper motor prior to generating each digital image.
 12. The apparatusaccording to claim 8, further comprising computer program instructionsexecutable by the processor, for performing the step of storing datapertaining to the radius of the object in each digital image.
 13. Theapparatus according to claim 8, further comprising computer programinstructions executable by the processor, for performing the step ofreporting the object's first property.
 14. The apparatus according toclaim 8, further comprising computer program instructions executable bythe processor, for performing the steps of applying force to the objectand measuring the return force of the object to determine a secondproperty of the object, wherein the second property is the elasticity ofthe object.